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Minggu, 17 Januari 2010

Are we finally seeing El Nino?

Are we finally seeing El Nino?

| Saturday, Jan 16 2010 02:53 PM

Last Updated Saturday, Jan 16 2010 09:55 PM

Bakersfield rainfall since July 1 totaled 2.17 inches on Friday, compared to a normal 2.38 inches, according to the National Weather Service. January's total was .32 inches, down from the normal-to-date of half an inch.The skies sure haven't matched predictions of a strong rain- and snow-making El Nino winter this year, but that may be about to change.

But a series of storms beginning to arrive Sunday night and continuing through Friday is forecast to bring several inches of rain and feet of snow to California, including 1/2 inch to 2 inches of rain to Bakersfield, said KBAK Channel 29 meteorologist Miles Muzio.

And the Weather Service recently updated its forecast to say we're on "the low end of a strong El Nino year," said agency meteorologist Cindy Bean.

"There are lots of indications that a pattern shift is about to occur," said John Monteverdi, a professor of meteorology at San Francisco State University.

What will happen longer-term is the focus of much talk.

"Odds are good to see some pretty good storms later in the winter," said Tim Barnett, a climate researcher at the Scripps Institution of Oceanography in San Diego. "How much rain, nobody can really tell you. All I can tell you is, it will be in the upper third of all the wet years."

A crucial point is that El Nino typically doesn't deliver its punch until later in the winter. So it's too early to fear a fourth drought year.

"I don't expect a whopper" of a rainy season, said Maury Roos, a hydrologist at the California Department of Water Resources. However, "I'm optimistic we will wind up getting a fairly decent January and February, probably above average."

El Nino is defined as a warming of the equatorial Pacific Ocean that's typically in place around Christmas -- hence the name, Spanish slang for "Christ child."

This warming of the Pacific typically alters weather patterns throughout the Western Hemisphere. In the United States, the Pacific Northwest usually gets drier and the Southwest wetter.

Central California, however, sits between these effects, so El Nino effects here can go either way. The Sierra Nevada snowpack -- all-important to the state's water supplies -- is also hard to predict in an El Nino winter.

Bean said we'll have to see how wet the snowpack is.

Muzio has high hopes for Mother Nature not only because of oceanic temperature anomalies but the fact many three-year droughts are punctuated by a rainy period.

"I'm completely optimistic this will be a turnaround year as far as the drought goes," Muzio said.

But what happens in Bakersfield this week and beyond is always questionable, he said, because of the rain shadow effect. Oftentimes downsloping winds warm and dry the air, robbing us of precipitation.

Bill Patzert, a climatologist at the NASA Jet Propulsion Laboratory in Pasadena, doubts this year's El Nino will bring major rains. He said its effect is muted by another phenomenon called the Pacific Decadal Oscillation, a longer-term change that is actually trending toward cooler ocean temperatures.

A more ambitious prediction comes from Gregg Suhler, whose company, Dynamic Predictables in Columbia, Mo., developed a unique forecasting tool called ATLAS.

Unlike traditional forecasting that relies on climate observations and historical trends, ATLAS uses thermodynamic principles to tap into recurring energy cycles that drive global weather.

Simply put, Suhler said, there is a certain amount of energy in the atmosphere that has to be spent every year in the form of storms. If it isn't -- for instance, during a stretch of drought years -- that energy eventually builds up to produce very big storms on a regular cycle.

"January and February are looking to be a really wet sucker," Suhler said. "We want people to know about it."

Experts in conventional forecasting are skeptical.

"Over the last decade, we've had a lot of false alarms about El Nino," Patzert said. "As you look back in the historical record, there really haven't been that many of what I call 'macho El Ninos.' "

On the other hand, it's worth looking at the winter of 1994-95. It started out dry. Californians feared that one of the worst droughts in history -- officially recorded from 1987 to 1992 -- wasn't really over.

Then El Nino caused major floods in many areas of the state in January and March 1995, including $220 million in damage and 28 deaths. "It turned out to be a heavy year when it was done, but it was a late bloomer," Roos said.

- Matt Weiser of The Sacramento Bee and Californian government editor Christine Bedell contributed to this report.

http://www.bakersfield.com/news/local/x113240137/Are-we-finally-seeing-El-Ni-241-o

Rabu, 13 Januari 2010

Washington snowpack below average so far

Washington snowpack below average so far

El Nino is shaping up as expected for the Pacific Northwest this winter, resulting in warmer temperatures, drier conditions and below-average mountain snowpack in Washington, the federal government said Tuesday.

Associated Press Writer

YAKIMA, Wash. —

El Nino is shaping up as expected for the Pacific Northwest this winter, resulting in warmer temperatures, drier conditions and below-average mountain snowpack in Washington, the federal government said Tuesday.

El Nino is a periodic warming of the water in the tropical Pacific Ocean accompanied by changes in air pressure and winds that can influence weather worldwide. In the Pacific Northwest, that generally means warmer and drier conditions, with above-average precipitation in the Southwest.

The warmer and drier conditions this year have resulted in mountain snowpack levels that are below average across Washington state, except on the Olympic Peninsula, said Scott Pattee, water supply specialist for the USDA's Natural Resources Conservation Service.

It's too early to know if those conditions will continue for the rest of the winter, but weather forecasters predict above-average temperatures through March, he said.

That could present challenges for water managers and water users later this summer, who rely on mountain snowpack to feed rivers and streams and fill lakes and reservoirs as it melts. Seventy to 80 percent of Washington's surface water supplies come from mountain snowmelt in the summer.

After above-average precipitation in October and heavy snowfall in November, Washington was on track for a good winter, Pattee said.

"But come December, Mother Nature just turned the faucet off," he said. "Typically, by this time, we should have a solid 50 percent of our snowpack on the ground and we're 10-15 percent behind on that right now."

Last month, the Pacific Northwest experienced the 14th-coldest December since 1895. It was also the 11th-driest December for Washington state.

The NRCS measures the depth and water content of snow at more than 100 locations around the state. That data is used to estimate how much water will flow down rivers and streams and into reservoirs as the snow melts.

Water shortages have been a regular problem in parts of the state in recent summers.

In Eastern Washington, snowpack levels ranged from 56 percent of average in the Spokane River basin to 89 percent of average in the Walla Walla area. West of the Cascades, snowpack in the central Puget Sound area registered at 72 percent of average, while the Olympic Peninsula came in at 123 percent of average.

http://seattletimes.nwsource.com/html/localnews/2010773214_apwamountainsnowpack1stldwritethru.html?syndication=rss

Rabu, 26 Agustus 2009

El Nino Modoki

El Nino Modoki Fenomena Baru
SENIN, 24 AGUSTUS 2009 | 08:12 WIB

JAKARTA, KOMPAS.com — Fenomena El Nino atau menghangatnya suhu muka laut di Samudra Pasifik mulai menggejala akhir Mei lalu dan cenderung menguat pada bulan ini. Namun, melihat pola dan lokasi ”kolam panas”—areal permukaan laut yang menghangat—ada kecenderungan versi baru El Nino yang disebut El Nino Modoki.

Hal ini diungkapkan pakar cuaca dari Teknologi Inventarisasi Sumber Daya Alam Badan Pengkajian dan Penerapan Teknologi (TISDA-BPPT), Fadli Syamsuddin, Jumat (21/8), melalui SMS. ”Ada kecenderungan anomali mengarah ke El Nino Modoki. Untuk memastikan, harus melihat kondisi terakhir,” ujarnya.

El Nino yang umumnya ditandai terjadinya anomali suhu muka laut di kawasan khatulistiwa di Samudra Pasifik disebut kolam panas. Hal ini mengakibatkan suplai uap air tinggi di kawasan Peru sehingga mengakibatkan banyak hujan di wilayah itu, sebaliknya kekeringan di wilayah Asia, terutama Indonesia.

Berbeda dengan El Nino, munculnya Modoki, bahasa Jepang, yang berarti ”serupa tapi berbeda”, ditunjukkan oleh adanya ”kolam panas” yang terkonsentrasi hanya di bagian tengah Samudra Pasifik. Bagian timur dan barat Pasifik tetap dingin.

Kondisi ini menyebabkan rendahnya suplai uap air atau terbentuknya awan hujan di Peru dan di timur Indonesia. Sejauh ini dari riset yang dilakukan peneliti Badan Riset Kelautan Jepang (Jamstec), wilayah Indonesia belum banyak diteliti. Fenomena ini juga baru dipublikasikan pada 2004 oleh peneliti Jamstec, tutur Fadli, yang meraih doktornya di Jepang.

Riset El Nino Modoki juga dilakukan peneliti dari Georgia Institute of Technology. ”Umumnya, El Nino menyebabkan menurunnya kejadian badai di Atlantik. Namun, tipe baru ini justru meningkatkan badai,” ujar Peter Webster, guru besar di Georgia Tech’s School of Earth and Atmospheric Sciences.

Menurut penelitian Webster yang muncul pada Jurnal Science edisi Juli lalu, El Nino Modoki lebih mudah diprediksi dibandingkan dengan El Nino. El Nino berubah menjadi Modoki oleh osilasi alami El Nino atau merupakan respons El Nino terhadap menghangatnya atmosfer atau karena La Nina mengubah struktur El Nino. (YUN)



Sumber : KOMPAS

http://sains.kompas.com/read/xml/2009/08/24/08124679/el.nino.modoki.fenomena.baru